Steppers stalling

[garymiller397]

So it is not running as well as I thought. Can only reliably get about 60 ipm. With the 5mm screws, that is about 300 rpm on the motor. If I run it any faster, the motor will stall part way through running the program, destroying the project. I would have thought that the motor would be good for more than 300 rpm. I disconnected the screw and checked the movement of the gantry and it is moving very easily over the entire length of travel.

I have the kernel speed set at 35000 in Mach3 with an acceleration of 20 ipm., 1600 microsteps on 425 oz. Nema 23 motors, 48 v power supply. I have several questions that I hope some of you can answer.

Is it possible that I have a problem with the driver? All the other axis seem to work fine.
Would it be better to change to a Nema 34 motor or change the ballscrew to a 1610, effectively doubling the speed?
Could I go to a Nema 34 with a belt/or gear drive to double the ballscrew speed?
Some people have responded that I should get a Nema 34, approx. 6A with an inductance of 1.5 mh. What is the significance of the inductance? I have found motors with inductance ranging from 1.5 to 9 mh.

[jannos]

Is it possible that I have a problem with the driver? All the other axis seem to work fine.

If you are happy with the other axes speed, just use two ballscrews and motors for the gantry.

[ger21]

I'd say ot's extremely unlikely to be a driver issue. A simple test is to swap drivers with another axis.

Would it be better to change to a Nema 34 motor or change the ballscrew to a 1610, effectively doubling the speed?

Your asking two different questions here.

Just changing to a Nema 34 probably won't make a lot of difference.
Typically, the larger the motor, the faster the torque drops as rpm's increase, making the usable top speed even lower than the smaller motor.

Inductance basically dictates how fast torque drops off as rpm's increase.

Could I go to a Nema 34 with a belt/or gear drive to double the ballscrew speed?

Yes, but for it to work well, you'd also need a new drive, and an even bigger power supply.

You have two things working against you.
The 1605 screws, which will never be very fast.
And the 425oz motors, which don't have much torque at higher speeds, and really need at least 72V to get decent performance out of them. But even then, the 1605 screws will still limit your performance.